Results 71 to 80 of about 1,969,695 (207)

Revisiting the Chemical Composition of WD 1145+017: Impact of Circumstellar Disk Contamination on Photospheric Abundances

The Astrophysical Journal
We performed a chemical analysis of the asteroid-bearing white dwarf WD 1145+017 using optical and ultraviolet spectroscopic data from 25 epochs between 2015 and 2023.
Érika Le Bourdais, Patrick Dufour, Siyi Xu   +2 more
doaj   +1 more source

Commentary on the role of polyoxometalates in nature cybernetic loop

Natural Sciences, Volume 4, Issue 2-3, June-July 2024.
Polyoxometalates (POMs) are both synthetic and naturally occurring coordination compounds. In the biosphere, POMs can participate in many different life‐determining geochemical and biological processes. Future interdisciplinary research on POMs may reveal their potential for prebiotic and abiotic chemistry, as well as for the development of artificial ...
Kirill Yu. Monakhov
wiley   +1 more source

Dust-evacuated Zones near Massive Stars: Consequences of Dust Dynamics on Star-forming Regions

The Astrophysical Journal
Stars form within dense cores composed of both gas and dust within molecular clouds. However, despite the crucial role that dust plays in the star formation process, its dynamics is frequently overlooked, with the common assumption being a constant ...
Nadine H. Soliman, Philip F. Hopkins, Michael Y. Grudić   +2 more
doaj   +1 more source

The deep eclipses of RW Aur revisited by long‐term photometric and spectroscopic monitoring

Astronomische Nachrichten, Volume 345, Issue 4, May 2024.
Abstract RW Aurigae is a young stellar system containing a classical T Tauri star as the primary component. It shows deep, irregular dimmings, first detected in 2010. At the University Observatory Jena, we carried out optical follow‐up observations. We performed multiband (BVRI) photometry of the system with the Cassegrain‐Teleskop‐Kamera II and the ...
Oliver Lux, Markus Mugrauer, Richard Bischoff   +2 more
wiley   +1 more source

Circumstellar gas and dust in 68 Ophiuchi (A0IVe)

Astronomy & Astrophysics, 1995
We present photometry and spectroscopy of the A0IVe star 68 Ophiuchi, for which Vidal-Madjar et al. (1993) suspected the presence of a circumstellar disc of material similar to that found around beta Pic. The UV and optical continuum agrees well with a Kurucz model with parameters that are consistent with the spectral type. 68 Oph is detected at 12 and
Waters, L.B.F.M., van den Ancker, M.E., Baas, F., van der Bliek, N.S., Bontekoe, T.R., Geballe, T.R., Grady, C.A., Kester, D.J.M., Oudmaijer, R.D., Sandell, G., The, P.S., Vega, R., van Winckel, H.   +12 more
openaire   +2 more sources

Limitations of the modified blackbody fit method for determining molecular cloud properties

Astronomische Nachrichten, Volume 345, Issue 4, May 2024.
Abstract Achieving a comprehensive understanding of the star and planet formation process is one of the fundamental tasks of astrophysics, requiring detailed knowledge of the physical conditions during the different phases of this process. During the earliest stages, that is, concerning physical processes in molecular clouds and filaments, the column ...
Niko Zielinski, Sebastian Wolf
wiley   +1 more source

L1448 IRS3B: Dust Polarization Aligned with Spiral Features, Tracing Gas Flows

The Astrophysical Journal
Circumstellar disk dust polarization in the (sub)millimeter is, for the most part, not from dust grain alignment with magnetic fields but rather indicative of a combination of dust self-scattering with a yet unknown alignment mechanism that is consistent
Leslie W. Looney, Zhe-Yu Daniel Lin, Zhi-Yun Li, John J. Tobin, Martin Radecki, Syzygy Butte, Ian W. Stephens, Manuel Fernández-López, Haifeng Yang, Nickalas K. Reynolds, Patrick Sheehan, Woojin Kwon, Rachel Harrison, Allen North   +13 more
doaj   +1 more source

Hourglass Magnetic Field of a Protostellar System

Universe
An hourglass-shaped magnetic field pattern arises naturally from the gravitational collapse of a star-forming gas cloud. Most studies have focused on the prestellar collapse phase, when the structure has a smooth and monotonic radial profile.
Shantanu Basu, Xiyuan Li, Gianfranco Bino   +2 more
doaj   +1 more source

Characterizing the dynamical magnetosphere of the extremely slowly rotating magnetic O9.7 V star HD 54879 using rotational modulation of the Hα profile

Astronomische Nachrichten, Volume 345, Issue 4, May 2024.
Abstract The magnetic field in the O9.7 V star HD 54879 has been monitored for almost a decade. Spectropolarimetric observations reveal a rather strong mean longitudinal magnetic field that varies with a period of about 7.41 years. Observations in the Hα$$ \alpha $$ line show a variation with the same period, while the Hβ$$ \beta $$ line shows only ...
Manfred Küker, S. P. Järvinen, S. Hubrig, Ilya Ilyin, M. Schöller   +4 more
wiley   +1 more source

Atacama Large Aperture Submillimeter Telescope (AtLAST) science: Our Galaxy [version 1; peer review: 2 approved]

Open Research Europe
As we learn more about the multi-scale interstellar medium (ISM) of our Galaxy, we develop a greater understanding for the complex relationships between the large-scale diffuse gas and dust in Giant Molecular Clouds (GMCs), how it moves, how it is ...
Pamela Klaassen, Maria Beltrán, Alessio Traficante, Mark Booth, Kate Pattle, Jonathan Marshall, Joshua Lovell, Brandt Gaches, Alvaro Hacar, Nicolas Peretto, Caroline Bot, Doris Arzoumanian, Thomas Stanke, Gaspard Duchêne, Ana Duarte Cabral, Antonio Hales, David Eden, Patricia Luppe, Jens Kauffmann, Elena Redaelli, Sebastian Marino, Álvaro Sánchez-Monge, Andrew Rigby, Dmitry Semenov, Eugenio Schisano, Mark Thompson, Silvia Spezzano, Claudia Cicone, Friedrich Wyrowski, Martin Cordiner, Tony Mroczkowski, Doug Johnstone, Luca Di Mascolo, Minju Lee, Eelco van Kampen, Thomas Maccarone, Daizhong Liu, Matthew Smith, Amélie Saintonge, Sven Wedemeyer, Alexander Thelen   +40 more
doaj   +1 more source